Retractable power step remote drive

ABSTRACT

The present invention includes a foldable step assembly for a vehicle. The step assembly includes a linkage arrangement for connection to a vehicle and articulating a step assembly from a deployed position to a stowed position. A drive mechanism is positioned remotely from the step assembly and is operatively in communication with the linkage arrangement for articulating said step assembly between the deployed position to the stowed position.

FIELD OF THE INVENTION

The present invention relates to a retractable power step remote drive.

BACKGROUND OF THE INVENTION

There exists a packaging problem to include a motor drive arrangementfor a powered step due to limited space in the vehicle in typicallocations and especially for rear mounted bumper type retractable stepdevices. The primary objective is to provide an assembly that allows forremotely packaging a drive system in a suitable location in order tomechanically drive the mechanism for a retractable step.

This improvement is useable on existing powered retractable steps havingthe motor directly mounted to the hinge link mechanism. The advantage ofsuch products are the overall simplicity and lower cost for a drivesystem. The disadvantage of such devices are the restraints in packagingsize envelope due to location and orientation of the motor. This canoccur in the longitudinal, cross car and vertical directions on thevehicle due to the orientation of the motor.

SUMMARY OF THE INVENTION

The present invention includes a foldable step assembly for a vehicle.The step assembly includes a linkage arrangement for connection to avehicle and articulating a step assembly from a deployed position to astowed position.

A drive mechanism is positioned remotely from the step assembly and isoperatively in communication with the linkage arrangement forarticulating the step assembly between the deployed position to thestowed position.

The present invention provides a remote drive system which allows themotor to be located in a more suitable location in the general mountingarea of the step device to utilize available space and attachmentprovisions in the vehicle.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a front perspective view of an embodiment of the presentinvention.

FIG. 2 is a rear perspective view of the embodiment shown in FIG. 1.

FIG. 3 is a perspective view of an alternate embodiment of the presentinvention.

FIG. 4 is a detailed exploded view of the drive mechanism of theembodiment of FIG. 3.

FIG. 5 is a detailed perspective view of the worm gear drive mechanismof the embodiment of FIG. 3.

FIG. 6 is a rear perspective view of another alternate embodiment of thepresent invention.

FIG. 7 is a front perspective view of the embodiment of FIG. 6.

FIG. 8 is a detailed perspective view of the drive mechanism of theembodiment of FIG. 6.

FIG. 9 is a detailed perspective view of the drive mechanism of theembodiment of FIG. 6.

FIG. 10 is a perspective view of a further embodiment of the presentinvention.

FIG. 11 is a front perspective view of the embodiment of FIG. 10.

FIG. 12 is a detailed perspective view of the drive mechanism of theembodiment of FIG. 10.

FIG. 13 is an exploded perspective view of the drive mechanism of FIG.12.

FIG. 14 is a perspective view of the drive mechanism of FIG. 13assembled.

FIG. 15 is an alternate embodiment of a drive mechanism of the presentinvention.

FIG. 16 is and exploded view of the drive mechanism of FIG. 15.

FIG. 17 is a perspective view of the drive cable arrangement of FIG. 16.

FIG. 18 is a perspective view of the embodiment of the invention shownin FIG. 3 employed on a side step for attachment to the rocker panel ofa vehicle.

FIG. 19 is a perspective view of the embodiment of the invention shownin FIG. 6 employed on a side step for attachment to the rocker panel ofa vehicle.

FIG. 20 is a perspective view of the embodiment of the invention shownin FIG. 10 employed on a side step for attachment to the rocker panel ofa vehicle.

FIG. 21 is a perspective view of the embodiment of the invention shownin FIG. 1 employed on a side step for attachment to the rocker panel ofa vehicle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

The invention includes four different methods to remotely locate a drivemotor from a drive shaft of a linkage shown in the attached figures.Referring now to all the figures, there is shown a foldable stepassembly 1, 2, 3, 4, 5, 6, 7, 8 each implementing one of four differenttypes of drive mechanisms referred to herein as drive mechanism 100,200, 300, 400; each corresponding to four different embodiments of theinvention used for moving a step 12, 12′ between a retracted positionand a deployed position for accessing portions of a vehicle. Eachfoldable step assembly 1, 2, 3, 4, 5, 6, 7, 8 includes a common linkagethat connects between the step 12, 12′ and the drive mechanism100,200,300,400. FIGS. 1-17 show the details of each drive mechanism100, 200, 300, 400, which is used in connection with step 12 on thefoldable step assembly 1, 2, 3, 4, while FIGS. 18-21 show drivemechanism 100, 200, 300, 400 being used on step 12′ on the foldable stepassembly 5, 6, 7, 8. Foldable step assembly 5, 6, 7, 8 differs from thefoldable step assembly 1, 2, 3, 4 in that the step 12′ is larger andincludes a follower link 14 that is shown as not being motorized,however it is within the scope of this invention for the follower link14 to be driven by a motor either using an independent motor or by usinga connection to the drive mechanism 100, 200, 300, 400.

A linkage 11 has some common components extending between the step 12,12′ and drive mechanism 100, 200, 300, 400. The linkage is a four barlinkage that includes a drive arm 16 connected to the step 12,12′ at apivot connection 22, and a follower arm 18 connected to the step 12, 12′at a pivot connection 24. The drive arm 16 and a follower arm 18 arepivotally connected to a base 20 with the follower arm 18 pivotallyconnected at a pivot 26 and the drive arm 16 pivotally connected at adrive shaft 28. The base 20 is connectable to a vehicle. The drive shaft28 receives rotational force from the drive mechanism 100, 200, 300, 400selected.

One limitation with providing motorized step assemblies on vehicles isthat the vehicle packaging constraints limit being able to connect amotor directly to the drive shaft 28. The present invention addressesthis issue because each drive mechanism 100, 200, 300, 400 employs adifferent mechanism to transfer rotational force from a motor to thedrive shaft 28, while allowing the motor to be mounted at a locationdistant from the drive shaft 28. The details of various drive mechanisms100, 200, 300, 400 that allow the motor to be mounted apart from thedrive shaft 28 will now be described.

Referring now to FIGS. 1, 2 and 21 the foldable step assembly 1, 5 withlinkage 100 will now be described. The drive mechanism 100 is referredto as a “bell crank assembly.” The drive mechanism 100 has a motor 102having an output shaft 104 that connects to the motor 102 through atransmission 106 that includes a gear train in a housing that is drivenby the motor 102. The output shaft is connected at a spatial distance dfrom the drive shaft 28. It is within the scope of this invention forthe motor 102 to directly drive the output shaft 104 depending on thesize of the motor and needs of a particular application.

The motor 102 can be any suitable motor capable of providing rotarymotion. In the present embodiment of the invention the motor 102 is adirect current motor that is capable of rotating bi-directionally. Theoutput shaft 104 has an axis AA that is typically parallel with an axisB-B of the drive shaft 28, this allows the motor 102 to be locateddistant from the drive shaft 28, thereby freeing up space adjacent thedrive shaft 28, which could limit possible locations that the stepassembly 1,5 could be mounted. The distance between axis A-A and axisB-B is the spatial distance d.

The drive mechanism 1, 5 includes a first arm 108 connected to theoutput shaft 28 using a clamp 110 connection. The first arm 108 isconnected to a second arm 112 at pivot 114. The second arm 112 at asecond end has a pivot 116 that connects to a driven arm 118. The drivenarm 118 has a clamp 110′ that connects to the drive shaft 28, wherebyallowing rotational force from the motor 102 to be transferred from theoutput shaft 104, through the first arm 108, second arm 112 and drivenarm 118, thereby rotating the drive shaft 28, which then causes the link11 to move between the extended position or retracted position dependingon the direction that the motor 102 turns the transmission 106 andoutput shaft 104. As shown in FIG. 21 foldable step assembly 5 the drivemechanism 100 is also useable on a step 12′ which is a full length powerrunning board. It is also within the scope of this invention for theactuator 100 to be used on a side box step, or a rear bumper type stepsimilar to the foldable step assembly 1 shown in FIGS. 1 and 2.

Referring now to FIGS. 3-5 and 18 the foldable step assembly 2, 6 withlinkage 200 will now be described. The drive mechanism 200 is alsoreferred to as a “remote motor torque transfer shaft type”. Thisincludes a motor 202 connected to a torque transfer shaft 204 thatconnects to a transmission 206 connected to the base 20 that ultimatelyconnects to the drive shaft 28 of the linkage 11. The transmission 206has a worm gear 208 in the transmission 206 and rotatably positioned ona bearing 207, 207′. The worm gear 208 is in mesh engagement with a gear210 rotatably connected to drive shaft 28 of the linkage 11. The torquetransfer shaft 204 of the drive mechanism 200 includes a spherical hextype universal joint design that has a first male connector 212 that isreceived by a first female connector 214 which is part of or connectedto an output shaft of the motor 202. At the opposite end of the torquetransfer shaft 204 is a second male connector 216 connected to the worm208 that is received by a second female connector 218 formed on thesecond end of the torque transfer shaft 204. The second male connector218 extends through the housing of the transmission 206 and has a seal209 that circumscribes the where the second male connector 216 extendsoutside of the housing of the transmission 206.

When the motor 202 rotates the first female connector 214 is driven bythe motor 202, which then rotates the torque transfer shaft 204 throughthe connection of the first female connector 213 with the first maleconnector 212. The rotation of the torque transfer shaft 204 rotates thesecond female connector 218, which connects to the second male connector216, thereby causing rotation of the worm gear 208. The rotation of theworm gear 208 causes the gear 210 to rotate because the mesh engagementof the threads of the worm gear 208 with the teeth of the gear 210. Thegear 210 is fixed to the drive shaft 28, thereby causing the drive shaft28 to rotate with the gear 210. When the drive shaft rotates 28 thelinkage 11 and the step 12, 12′ will move between the retracted positionor the extended position depending on the direction that the motor 202rotates.

While the first female connector 214 is shown as an output of the motor202 and the first male connector 212 is depicted as being on the end ofthe torque transfer shaft 204 it is within the scope of this inventionfor these connections to be reversed. Likewise, the second maleconnector 216 is shown as being connected to the worm gear 208 and thesecond female connector 218 is shown as being formed on the end of thetorque transfer shaft 204, it is also within the scope of this inventionfor these connections to be reversed. It should be noted that othertypes of universal joint designs such a pin and block type or CV stylecould be employed to accomplish the drive with angled axis of the motorshaft, torque transfer shaft and worm axis. This remote drive can beused with other step types as shown in FIG. 18. The present embodimentof the invention allows the motor 202 to be linearly positioned at aspatial distance d′ from the base 20 that is determined by the length ofthe torque transfer shaft 204.

Referring now to FIGS. 6-9 and 19 the foldable step assembly 3, 7 withlinkage 300 will now be described. The drive mechanism 300 is alsoreferred to as a “Remote motor flex shaft type”. This includes a motor302 connected to a flex shaft core 304 inside a cable casing 305 thatconnects to a transmission 306. More specifically the flex shaft core304 is connected to a worm gear 308 within the transmission 306, theworm gear 308 has threads in mesh with teeth of a gear 310 rotatablyconnected to drive shaft 28 of linkage 11. The flex shaft core 304 is ahelically wound core of wired with multiple layers in alternatinghelical directions over top of each other. The ends of the flex shaftfore 304 typically have square shaped ends 312, 314. The square shapedends 312, 314 engaged with one of a first female connector 316 rotatablyconnected to the motor 302 or a second female connector 318 connected toor formed on the worm gear 308. The first female connector 316 andsecond female connector 318 are square shaped to form a mated fittingwith one of the square ends 312, 314 of the flex shaft core 304. Theflex shaft core 304 is limited in torque transmission capability bytheir length and bend radius but still provide a remote location for themotor 302.

When the motor 302 rotates the first female connector 316 is driven bythe motor 302, which then rotates the flex shaft core 304 through theconnection of the first female connector 316 and square end 312. Therotation of the flex shaft core 304 rotates the square end 314, whichrotates the second female connector 318 and the worm gear 308. Therotation of the worm gear 308 causes the gear 310 to rotate because themesh engagement of the threads of the worm gear 308 with the teeth ofthe gear 310. The gear 310 is fixed to the drive shaft 28, therebycausing the drive shaft 28 to rotate with the gear 310. When the driveshaft 28 rotates the linkage 11 and the step 12, 12′ will move betweenthe retracted position or the extended position depending on thedirection that the motor 302 rotates. The use of the flex shaft core 304allows the motor 302 to be positioned at great distances and non-linearlocations with respect to the base 20. The present embodiment of theinvention allows the motor 302 to be linearly positioned at a spatialdistance d″ from the base 20 that is determined by the length of theflex shaft core 304.

Referring now to FIGS. 10-17 and 20 the foldable step assembly 4, 8 withlinkage 400 will now be described. The drive mechanism 400 is alsoreferred to as a “Remote motor push/pull cable type.” The motor 402 isattached to a drive housing 403 which is connected to a cable casing 405that connects between the drive housing 403 and a transmission 406attached the base 20. The cable casing 405 connects to a casingconnector 407 on the drive housing 403. Within the drive housing 403there is a gear 408 with teeth 410 that engage that is in meshengagement with a cable core 412 capable of sliding within the cablecasing 405. The cable core 412 has a helically wound wire 414 wrappedaround an inner core 416. This helically wound wire 414 has a helicalpitch length equal to the circular tooth pitch of the teeth 410 of thegear 408.

The opposite end of the cable casing 405 from the drive housing 403there is a casing connector 418 that connects to a casing lock 420formed on the housing of the transmission 406. The cable core 412terminates in the housing of the transmission 406 at a lug 422 fixed toan end of the cable core 412. The lug 422 is held in place by a trunnion424 that is connected to a link 426 that is slidably positioned in abore 429 of the housing of the transmission 406. The link 426 ispivotally connected to a drive link 430, which has a clamp 432, thatlocks onto and rotates the drive shaft 28 of the linkage 11.

During operation the motor 402 rotates the gear 408 in one of twodifferent directions, thereby pushing or pulling the cable core 412through the cable casing 405. When the cable core 412 is pulled throughthe cable casing 405 away from the transmission 406 the lug 422 pullsthe trunnion 424 and the link moves in the bore 428 toward the casinglock 420. This causes the link 426 to rotate the drive link 430 andoutput shaft 28 counter clockwise, thereby moving the link 11 and step12, 12′ to the extended direction. When the motor 402 rotates the gear408 in a second one of two different directions the cable core 412 ispushed through the cable casing 405. When the cable core 412 is pushedthrough the cable casing 405 toward the transmission the lug 422 pushesthe trunnion 424 and the link 426 moves in the bore 428 away from thecasing lock 420. This causes the link 426 to rotate the drive link 430and the output shaft 28 clockwise, thereby moving the link 11 and thestep 12, 12′ to the retracted position.

Referring now to FIG. 13 the details of the transmission 406 are shownin exploded view. The trunnion 424 has a tab with an aperture 434 thatrotatably receives a post 436 of the link 426. The drive link 430 alsohas an aperture 438 that rotatably receives a post 440 of the link 426.The clamp 432 of the drive link 430 is connected to the drive shaft 28of the drive arm 16, which rotates along with the follower arm 18 inresponse rotational force from the motor 402. The present embodiment ofthe invention allows the motor 402 to be linearly positioned at aspatial distance d′″ from the base 20 that is determined by the lengthof the cable core 412.

All of the drive types described here provide a means to mechanicallydrive the retractable step from stow to deploy positions with the motoritself in a remote location more suitable packaged away from the drivelinkage of the step assembly. The various methods offer a variation incost and complexity and package ability to best suit the application.

The description of the invention is merely exemplary in nature and,thus, variations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

What is claimed is:
 1. A foldable step assembly for a vehiclecomprising: a base connectable to a vehicle; a linkage connected to thebase, the linkage is further connected to a step that is moved by thelinkage between a deployed position to a stowed position; a motor havingan output shaft positioned at a spatial distance from the base of thelinkage; and a drive mechanism connected between the motor and thelinkage for transferring force across the spatial distance from theoutput shaft to the linkage for articulating the linkage and the stepbetween an extended position and retracted position.
 2. The foldablestep assembly of claim 1 further comprising: a transmission connected toand driven by the motor, the transmission having an output shaft with anaxis; a bell crank assembly with a first arm connected to the outputshaft of the transmission, a second arm pivotally connected to the firstarm and extending across a portion of the spatial distance, a driver armpivotally connected to the second arm and extending across a portion ofthe spatial distance, the driver arm is connected to a drive shaft ofthe linkage.
 3. The foldable step assembly of claim 2 wherein the outputshaft of the transmission has an axis and the drive shaft of the linkagehas an axis that is parallel to the axis of the output shaft of thetransmission.
 4. The foldable step assembly of claim 3 wherein thespatial distance is equal to the distance between the axis of the outputshaft and the axis drive shaft.
 5. The foldable step assembly of claim 1further comprising: a transmission connected to the base, thetransmission includes a worm gear drivingly engaged to the linkage,wherein the drive mechanism includes a torque transfer shaft connectedto the output shaft of the motor and the worm gear so that rotation ofthe torque transfer shaft rotates the worm gear.
 6. The foldable stepassembly of claim 5 further comprises a drive shaft of the linkageconnected to a gear located within the transmission, wherein the gear isin mesh engagement with the worm gear and rotation of the worm gearrotates the gear and drive shaft.
 7. The foldable step assembly of claim5 wherein the spatial distance is equal to the length of the driveshaft.
 8. The foldable step assembly of claim 5 further comprising: afirst male connector on the torque transfer shaft that is received by afirst female connector on the output shaft of the motor; and a secondmale connector connected to the worm gear that is received by a secondfemale connector formed on the second end of the torque transfer shaft.9. The foldable step assembly of claim 1 further comprising: atransmission connected to the base, the transmission includes a wormgear drivingly engaged to the linkage, wherein the drive mechanismincludes a cable casing with a flex shaft core slidable in the cablecasing, wherein the cable casing connects to both the output shaft ofthe motor and the worm gear and rotation of the flex shaft core rotatesthe worm gear.
 10. The foldable step assembly of claim 9 furthercomprises a drive shaft of the linkage connected to a gear locatedwithin the transmission, wherein the gear is in mesh engagement with theworm gear and rotation of the worm gear rotates the gear and the driveshaft.
 11. The foldable step assembly of claim 9 wherein the spatialdistance is equal to the length of the cable core.
 12. The foldable stepassembly of claim 9 further comprising: a first square end on a firstend of the cable core and a second square end on a second end of thecable core; a first female connector connected to the output shaft ofthe motor, wherein the first square end of the cable core is received bythe first female connector; and a second female connector connected tothe worm gear of the transmission, wherein the second square end of thecable core is received by the second female connector.
 13. The foldablestep assembly of claim 1 further comprising: a transmission connected tothe base; a drive housing connected to the motor and having a gear withteeth connected to and rotatably driven by the motor; a cable casingconnected between the transmission and the drive housing; a cable coreslidably positioned in the cable casing, wherein the cable core hasfeatures on the surface capable of meshing with the gear in the drivehousing so that rotation of the gear in the drive housing moves slidesthe cable core in the cable casing, wherein one end of the cable core islocated in the transmission and slides in the transmission in responseto rotation of the gear in the drive housing; a drive link connected tothe drive shaft of the linkage, the drive link is located in thetransmission and is operatively connected to the end of the cable coreso that when the cable core slides in the transmission the drive linkrotates the drive shaft of the linkage.
 14. The foldable step assemblyof claim 13 wherein the cable core includes an inner core with a helicalwire wound on the inner core to form the features on the cable core. 15.The foldable step assembly of claim 13 wherein the spatial distance isequal to the length of the cable casing.
 16. The foldable step assemblyof claim 13 further comprising: a lug formed on the end of the cablecore located in the transmission; a trunnion connected to the lug; alink connected to the trunnion and the drive link, wherein the lug,trunnion and link are slidable in a bore of the transmission and morethe drive link to rotate the drive shaft.
 17. The foldable step assemblyof claim 1 further comprising a step connected to the linkage.
 18. Thefoldable step assembly of claim 15 further comprising a follower linkconnected to the step.
 19. A foldable step assembly for a vehiclecomprising: a base connectable to a vehicle; a linkage connected to thebase, the linkage is further connected to a step that is moved by thelinkage between a deployed position to a stowed position; a motor havingan output shaft positioned at a spatial distance from the base of thelinkage; a drive mechanism connected between the motor and the linkagefor transferring force across the spatial distance from the output shaftto the linkage for articulating the linkage and the step between anextended position and retracted position, a transmission connected tothe base, the transmission includes a worm gear drivingly engaged to thelinkage, wherein the drive mechanism includes a cable casing with a flexshaft core slidable in the cable casing, wherein the cable casingconnects to both the output shaft of the motor and the worm gear androtation of the flex shaft core rotates the worm gear, wherein thespatial distance is equal to the length of the cable casing; and a driveshaft of the linkage connected to a gear located within thetransmission, wherein the gear is in mesh engagement with the worm gearand rotation of the worm gear rotates the gear and the drive shaft. 20.The foldable step assembly of claim 19 further comprising: a firstsquare end on a first end of the cable core and a second square end on asecond end of the cable core; a first female connector connected to theoutput shaft of the motor, wherein the first square end of the cablecore is received by the first female connector; and a second femaleconnector connected to the worm gear of the transmission, wherein thesecond square end of the cable core is received by the second femaleconnector.
 21. The foldable step assembly of claim 19 furthercomprising: a drive housing connected to the motor and having a gearwith teeth connected to and rotatably driven by the motor; wherein thecable casing connected between the transmission and the drive housing;wherein the cable core is slidably positioned in the cable casing,wherein the cable core has features on a surface capable of meshing withthe gear in the drive housing so that rotation of the gear in the drivehousing moves slides the cable core in the cable casing, wherein one endof the cable core is located in the transmission and slides in thetransmission in response to rotation of the gear in the drive housing; adrive link connected to the drive shaft of the linkage, the drive linkis located in the transmission and is operatively connected to the endof the cable core so that when the cable core slides in the transmissionthe drive link rotates the drive shaft of the linkage.
 22. The foldablestep assembly of claim 21 wherein the cable core includes an inner corewith a helical wire wound on the inner core to form the features on thecable core.
 23. The foldable step assembly of claim 21 furthercomprising: a lug formed on the end of the cable core located in thetransmission; a trunnion connected to the lug; a link connected to thetrunnion and the drive link, wherein the lug, trunnion and link areslidable in a bore of the transmission and more the drive link to rotatethe drive shaft.
 24. The foldable step assembly of claim 19 furthercomprising a step connected to the linkage.
 25. The foldable stepassembly of claim 24 further comprising a follower link connected to thestep.